I seem to have a small weep from the seam at the back of the tank on my Monster S4R. It looks to possibly be the seam by the hinge, rather than the bottom edge on the Left. What's the best option without having to have the tank re-sprayed afterwards? If it is the rear seam I might be able to live with it for a while if it is covered by the seat.
This is one of 2 competing companies, https://www.caswelleurope.co.uk/fuel-tank-sealing-kits/ and this is the other, https://www.frost.co.uk/brands/por-...MIn-DnrImShQMVApRQBh1TSQT2EAAYASAAEgI_-_D_BwE that offer 1 solution. Andy
Weld it and paint it. It's not what you want to hear but then it's done properly. It's not getting better and I haven't heard many success stories with sealers. Once that shite is in there it makes later welding difficult to impossible.
Thanks Andy, I have heard of the POR15 sealer before, I may get some and give it a go. Fortunately, mine is only a weep, which leaves a brown gum like substance on the side panel and back of the engine after a while.
As Petsmith says welding a new section in and re spraying the tank after is the most positive way to go. I did similar to my sieve like 900ss tank then coated the inside using Por15 sealer. With new decals you’d never know, except for some hawk-eyes on here.
Unfortunately welding is the only way to go (as said) on this occasion, and it's not an easy job to do properly as the fatigue crack causing the leak is coming from (usually) the edge of a spotweld under the hinge plate. I have seen people just weld up all the way around the whole periphery of the plate plus the hole in the centre which is the easiest solution overall.
This is a common issue with original style monsters. The probable cause is lifting the tank on its hinge while its holding a decent amount of fuel .. or more probably propping a full tank up on the one-sided tank prop which causes twisting at the hinge. For future reference the best tank prop is a length of timber about 18 inches long from the airbox to the undertank recess. There has been historical discussion on the UKMOC forum. The upshot was that brazing was decided to be the best option .. all around the hinge and around the central hole as well. If memory serves, the lower and more focused heat involved has enabled this to be done without damage to the visible paintwork. Have a search on UKMOC (uk monster owners' club).
Brazing is great when you have two faces to join with a large surface area, Chasing fatigue cracks in metal is better off welded in the long run. I would and have oxyacetylene welded in the past, but if you are really worried about distortion and excess heat then you can get somebody to Tig weld.
